Activities conducted within the context of this project include: 1. Make a telephone contact with eligible BLSA participants to establish current status and williness to attend a BLSA clinic visit, participate in the home visit program or complete a telephone interview. 2. In BLSA participants enrolled in the home visit program, conduct an extensive assessment of health status, aimed at ascertaining multiple health-related outcomes (cognitive impairment, dementia, mobility limitation, ADL disability, frailty, fatigability and major health conditions CHD, cancer, etc.). 3. In BLSA participants enrolled in the home visit program, collect a blood sample to be used for basic tests of clinical chemistry and storage of cells, serum and plasma. 4. Provide participants and their families with a detailed description of the study, and obtain informed consent for participation, including consent for the use of biological specimens. 5. Create a database with tracking information and all information collected over the telephone interview and during in person home visits, maintaining full compatibility with the BLSA core database.